The present invention relates to an anisotropic conductive film capable of exhibiting a conductivity only in the thickness direction thereof, which is used to be interposed between opposed circuits for connecting the circuits to each other through conductive particles contained in the film and also adhesively bonding them to each other by pressurizing and heating the film interposed therebetween.
An anisotropic conductive film is used to be formed between various terminals for adhesively bonding and also electrically connecting the terminals to each other. For example, it is used for connection of a FPC (Flexible Printed Circuit) and TAB (Taped Automated Bonding) to ITO terminals formed on a glass substrate of a liquid crystal panel.
In general, an anisotropic conductive film is characterized in that conductive particles are dispersed in an adhesive mainly containing an epoxy or phenol based resin and a hardener. As the adhesive, a one-component thermosetting type has been mainly used for the sake of convenience in use. Various attempts have been made to increase an adhesive strength of an anisotropic conductive film in order to obtain a stable reliability in connection even under a high temperature/high humidity environment.
The conventional anisotropic conductive film using an epoxy or phenol based resin, however, has a drawback in terms of low adhesive strength, poor workability and low heat/humidity resistance.